Yes, this is what I meant by CPUC stating that ADA preempts their own rule. However, transit agencies are notoriously cautious about relying on rulings like this. I personally guarantee should Caltrain pursue level boarding (a big if), they will still go through the process to get a waiver.

There is no waiver because there is no rule. (You still need a waiver from something related to worker access I don’t quite geometrically understand.)